1. Field of the Invention
The present invention relates to an image forming apparatus, a control method therefor, and a storage medium storing a control program therefor. Particularly, the present invention relates to a control method for power-saving of an image forming apparatus.
2. Description of the Related Art
An apparatus, such as a multifunctional peripheral (MFP), which is used in an office is required to save power at a high level, in recent years. Accordingly, a proposed MFP can reduce effective electric power by turning off power of devices that are not used in a standby mode in addition to controlling ON/OFF of the entire apparatus and using a power saving mode. For example, Japanese Laid-Open Patent Publication (Kokai) No. 2001-201986 (JP 2001-201986A) discloses a technique for saving power consumption of each device of an apparatus according to a function of a selected application by turning off power of a fixing device and a sheet feeding system during a facsimile receiving operation, and by turning off power of an operation panel and an image scanner device.
On the other hand, in order to obtain a high power saving effect in a MFP, it is possible to turn on power of respective devices, such as a printer device and a scanner device, individually. For example, it is possible to turn on power of the devices at the time when an original is placed on the scanner unit. However, the printer device is not necessarily operated, even if an original is placed on the scanner device. And therefore, if the power of the printer device turns on at the time when an original is placed on the scanner device, sufficient power saving effect will not be obtained. On the other hand, if the power of the printer device is turned on after determining that the printer device will be operated, warming-up of the printer device will take time, which gives an impression of bad response of the apparatus to a user.